Exemplary embodiments of the disclosure relate to an image sensor and an image processing system including the same, and more particularly, to an image sensor including an auto-focusing pixel having a 2-photo diode (PD) structure and an image processing system including the same.
Complementary metal-oxide semiconductor (CMOS) image sensors are solid type imaging devices using a CMOS. CMOS image sensors are inexpensive to manufacture and have a small size to reduce power consumption, compared to charge-coupled device (CCD) image sensors employing high-voltage analog circuits. As the performances of CMOS image sensors have been improved more than at the initial development stage thereof, the CMOS sensors are installed mainly in home appliances including portable devices, such as smart phones, digital cameras, etc.
In a pixel array included in a CMOS image sensor, each pixel includes a photoelectric conversion element. The photoelectric conversion element may generate an electrical signal that changes according to the amount of light incident thereon. The CMOS image sensor may synthesize an image by processing the electrical signal.
Recently, cameras have been developed to have an auto-focusing function of automatically bringing a camera into focus. In order to perform the auto-focusing function, a signal on which auto-focusing information is based should be generated. Recently, many attempts have been made to generate auto-focusing information by adding pixels for auto-focusing into a pixel light-receiving unit included in a CMOS image sensor without using an additional optical system.